In the initial stage, many laser apparatuses were introduced to treat skin ailments. These laser apparatuses are appropriate for curing a particular skin ailment by selecting the laser light of a wavelength necessary for treating specific ailments and locally irradiating the selected laser light on the corresponding skin part to be treated. However, said laser apparatuses have a lot of side effects, and particularly, it is hard to irradiate laser beams on the skin that has various skin ailments. That is to say, because each ailment needs proper laser beams, these ailments should be treated by using several laser beams if the patient wants to be treated due to the freckles or blemishes, the expanded blood vessels, and fine wrinkles or large pores on his or her face.
To solve such drawbacks, an intense pulsed light (hereinafter, IPL) apparatus, which simply cures various skin ailments by irradiating diverse wavelengths of lights at a time, has been developed by an American doctor Bitter, and is being widely used at the moment. The IPL apparatus employs a lamp flash that emits light having a wavelength of 350 nm to 1200 nm, and adjusts the wavelength of the emitted light with a filter, and generally, as the irradiation lamp, a Xenon lamp irradiates laser beams on the skin for three seconds, two to three times approximately.
Like mentioned above, when the IPL apparatus irradiates laser beams with the Xenon lamp, the amount of energy that is irradiated at a time should be controlled at a desired level. Further, the IPL apparatus has to supply regular power to a Xenon flash circuit in order to emit the irradiation energy of which the level is determined. For the lamp flash driving circuit of the IPL apparatus, a PAM (Pulse Amplitude Modulation) driving circuit mode, a PWM (Pulse Width Modulation) driving circuit mode, and a mixed type thereof are used.
FIG. 1 is a driving circuit diagram of a prior IPL apparatus that employs a PAM driving mode. Power supplied from a supply voltage 10 ranging from 100V to 240V is inputted to an output voltage-controlled constant voltage supplier 30 (for example, SMPS (Switching Mode Power Supply)) after noise has been removed by a noise filter 20. The output voltage-controlled constant voltage supplier 30 converts the inputted power into stable DC power, and supplies the DC power to a capacitor 80. When the user adjusts the irradiation energy of a Xenon lamp through a user interface 60, a corresponding adjustment signal is inputted to a controller 50, and the controller 50 precisely adjusts an output voltage of the output voltage-controlled constant voltage supplier 30 according to the adjustment signal. Further, if the controller 50 drives a Xenon lamp flash unit 40 through a trigger 70 at every proper time by using the energy supplied to the capacitor 80 from the output voltage-controlled constant voltage supplier 30, the energy stored in the capacitor 80 is instantly supplied to the Xenon lamp flash unit 40. Hence, if a voltage applied to the capacitor 80 is adjusted, a desired level of the energy supplied to the Xenon lamp flash unit 40 is obtained. In the PAM driving mode of FIG. 1, the amount of energy (that is, voltage values on both ends of the capacitor 80) supplied to the Xenon lamp flash unit 40 is adjusted in such a manner that the amount of energy delivered to the user's skin can be controlled precisely.
FIG. 2 is a driving circuit diagram of a prior IPL apparatus that employs a PWM driving mode. Power supplied from a supply voltage 10 ranging from 100V to 240V is inputted to an output voltage-controlled constant voltage supplier 30 (for example, SMPS (Switching Mode Power Supply)) after noise has been removed by a noise filter 20. The output voltage-controlled constant voltage supplier 30 converts the inputted power into stable DC power, and supplies the DC power to a capacitor 80. When the user adjusts the irradiation energy of a Xenon lamp through a user interface 60, a corresponding adjustment signal is inputted to a controller 50, and the controller 50 outputs a trigger signal for performing a proper PWM driving process to a trigger 70, and precisely controls the amount of energy supplied to the Xenon lamp flash unit 40. In this case, the controller 50 may adjust a charging voltage by transmitting a control signal even to the output voltage-controlled constant voltage supplier 30 when necessary. FIG. 3 is a graph for illustrating the amount of energy charged and discharged in accordance with time in the Xenon lamp flash unit 40 of the prior IPL apparatus that employs the PWM driving mode shown in FIG. 2. Like illustrated in FIG. 3, it could be understood that the Xenon lamp flash unit 40 is driven only in the oblique sections from the moment when a trigger signal is applied, while the energy is charged to the trigger time Tt from time 0. That is to say, in the PWM driving mode of FIG. 2, by controlling the width and intervals of the oblique time for the amount of energy supplied to the Xenon lamp flash unit 40, it is possible to precisely adjust the amount of energy delivered to the user's skin.
However, the prior IPL apparatus that employs the PAM driving mode in FIG. 1, the prior IPL apparatus that employs the PWM driving mode in FIG. 2, and the prior IPL apparatus that employs the mixed type thereof use the output voltage-controlled constant voltage supplier 30 in order to supply stable power to the capacitor 80. In this case, because the IPL is characterized in that DC current values outputted from the output voltage-controlled constant voltage supplier 30 use hundreds of milliamperes (mA) to tens of amperes (A), a high-capacity power source should be switched, whereby a high-priced output voltage-controlled constant voltage supplier 30 is essential. Further, it is problematic because an expensive noise filter 20 has to be equipped in order to remove noise of the power that is supplied to the high-capacity output voltage-controlled constant voltage supplier 30. Such a problem is now emerging since the more expensive noise filter 20 and the higher-priced output voltage-controlled constant voltage supplier 30 should be used if the capacitor 80 has to be charged at a faster speed in order to more often turn on the Xenon lamp flash unit 40 at every second.
In addition, when the output of the IPL apparatus is increased, the IPL apparatus may be used as a hair removing machine for removing hairs on legs, arms and the like. However, if the IPL apparatus is used as the hair removing machine, a higher output is necessary. Thus, when the driving circuit of the prior IPL apparatus is used, the higher-priced output voltage-controlled constant voltage supplier (30) and the more expensive noise filter (20) should be provided as well.